This invention relates to image scanners which generate image signals corresponding to the scanned images.
Scanners convert hard copy analog images on a media into image signals typically in the form of digital data. The media can be either transparent (for example, a photographic negative) or reflective (for example, a photographic paper print). The use of scanners has become widespread for a variety of applications, including storing, manipulating, transmitting and displaying or printing copies of the images. For example, images captured in photographic media can be converted to digital data and stored on compact discs for readout and display as a video image or for printing with various types of color printers. In order to capture the photographic image signal, an image frame is scanned with light, such as a line of light or a full frame of light, and the light transmitted through the image is detected, typically as three primary color light intensity signals, and then digitized. The digitized values may be formatted to a standard for video display and stored on compact disc, magnetic media, or other suitable storage. Scanners take a variety of forms and the various common aspects of film digitizing, particularly line illumination and linear CCD-based digitizers, are described in greater detail in U.S. Pat. No. 5,012,346. For example, in one common type of scanner a one-dimensional sensor (typically referenced as a line sensor or one-dimensional array) is used and the illumination source directs a line of light onto the image bearing media, which is then moved one line at a time to scan the complete image line by line. In another scanner type, a two-dimensional sensor (typically referenced as a two dimensional or area array) is used, and the illumination source illuminates the entire image at the same time, so that the complete image is scanned in a single exposure. Scanners with area arrays are simpler to construct and are often preferred. However, scanners with line sensors provide higher resolution at lower equipment cost. A sensor assembly of a typical color scanner includes both the sensor and suitable electronics, so as to provide a multi-color channel output signal representing the scanned image, with each color channel corresponding to a different spectral region (for example, red, green and blue channels, or cyan, magenta and yellow channels).
Recently, photographic images received at a photographic laboratory have been scanned to provide corresponding digital image signals. These image signals have then been used to generate index prints or provide images on storage media such as magnetic or optical disks, to upload the digital image signals to a remote storage location through a network (such as the Internet) for later access by customers. Systems and methods of the foregoing type are described, for example, in U.S. Pat. No. 5,760,916 and U.S. Pat. No. 5,760,917. The foregoing references, and all other references cited in the present application, are incorporated in this application by reference. It has also been suggested that the digital image signals can be used on a printer to produce the full-size customer image prints or other image products incorporating the customer images. Photofinishing laboratories and methods using digital images are described, for example, in the following U.S. Patent Applications all assigned to Eastman Kodak Co.: Ser. No. 09/087,014 filed May 29, 1998, titled xe2x80x9cIMAGE PROCESSINGxe2x80x9d; Ser. No. 09/107,571 filed Jun. 29, 1998, titled xe2x80x9cIMAGE MOVEMENT IN A PHOTOGRAPHIC LABORATORYxe2x80x9d; and S.N. (not yet known) filed Jul. 31, 1998, titled xe2x80x9cIMAGE QUEING IN PHOTOFINISHINGxe2x80x9d (inventors G. Bryniarski, B. Wilson, L Bovenzi; attorney docket number 78142).
Film scanners include a film gate typically having some means, such as a track of appropriate width, to guide a filmstrip. Previously, most consumer filmstrips were conventional 35 mm film. However, filmstrips of the recently introduced Advanced Photo Systems (xe2x80x9cAPSxe2x80x9d) formats are only 24 mm in width. Furthermore, the image sizes on an exposed APS filmstrip are of a different maximum width than those on a 35 mm filmstrip. Both conventional 35 mm and APS film formats are expected to coexist in the market for some time. Thus, photofinishing operations which receive consumer filmstrips for chemical developing and scanning, must either provide two different scanners (one for each format of film) or provide a single scanner which can handle both formats. It is preferable to have a scanner which can handle both film formats to keep total costs of a photofinishing system low. Thus, a single scanner capable of handling both formats must accommodate both the different physical widths of the filmstrips as well as the different image sizes. Different filmstrip widths can be accommodated by using, for example, interchangeable film gates dimensioned to guide the respective different width filmstrips. Different image widths can be accommodated by using different lens systems to correctly focus the different sized images of the different formats, onto the same sensor. In such an arrangement though, the lens system must typically be pulled back from the film gate to allow access to it for changing when film formats are changed. When the film gate has been replaced each of the lens systems must be re-focussed since even small movements of lens system along an optical axis between the film gate and a sensor, can substantially alter the focussing of an image in the gate onto the sensor. Even for scanners which are intended to scan only one film format, it may be necessary to pull the single lens system back from the film gate for cleaning and or repair. Such refocusing wastes time, particularly during the more frequent film gate changes that are likely to occur in a scanner constructed with interchangeable gates to handle different film formats, and therefore decrease productivity in the photofinishing laboratory.
It would be desirable then, to provide a scanner in which a lens system can be pulled back from a film gate to allow access to it, and which lens system can be rapidly repositioned over the film gate in a correct focal position relative to the sensor. It would particularly be desirable to provide such a scanner which has an interchangeable gate and at least two lens systems, to accommodate different filmstrip formats.
The present invention, then, provides in one aspect a scanner having a gate to receive a media carrying an image to be scanned. A frame is provided which is movable toward and away from the gate between a scanning position and a retracted position spaced further away from the gate than the scanning position. The scanner further includes a sensor and a lens mounted on the frame, which sensor and lens move with the frame between the scanning and retracted positions, so that the lens can focus at least part of an image in the gate onto the sensor.
In the various aspects of scanners of the present invention, there may be included a first driver connected to the frame, to move the frame and attached sensor and lens between the scanning and retracted positions. Further, movement may be allowed for the lens (sometimes referenced herein as a lens system) in a direction toward and away from the gate (that is, along an optical axis between the gate and the sensor when the frame is in the scanning position). However, having the sensor and lens attached to the frame so as to be essentially immovable relative to the frame in the direction toward and away from the gate, reduces the possibility of having to refocus a lens. Scanners of the present invention may also include an illumination system to illuminate an image in the gate.
In one aspect, at least a portion of the frame contacts the scanning gate when the frame is in the scanning position. Such an arrangement helps to position the frame, lens, and sensor in relation to the scanning gate. Other arrangements could be used though. In another aspect the frame and gate together have at least one set of mating members which, when mated, define the scanning position. Each such set may, for example, comprises a protrusion member and a receptacle member. In a particular aspect, the mating members may restrain movement of the frame in one, or three of the following directions, namely movement of the frame toward the gate, lateral movement of the frame with respect to the gate, and rotational movement of the frame with respect to the gate. Three sets of members may particularly, but not necessarily, be used to restrain movement in all three of the directions.
In another aspect of a scanner of the present invention, the scanner includes a sensor and at least two lenses mounted on the frame, which sensor and lenses move with the frame between the scanning and retracted positions. Each of the lenses is transversely movable in turn into an optical path between the gate and the sensor when the frame is in the scanning position, so as to focus at least part of an image in the gate onto the sensor. Such movement may be linear movement, or rotational movement about a common axis of rotation (such as when both lenses are mounted on a rotating turret). Movement can be accomplished by a second driver connected to the lenses to move each into and out of the optical path. Both lenses may be attached to the frame so as to be immovable relative to the frame in the direction toward and away from the gate, as described above.
The present invention further provides a method of scanning images carried by elongated films, using a scanner having a gate, a frame, and a lens and sensor both attached to the frame (which scanner may particularly be a scanner of the present invention). The method includes, when the frame is in a scanning position, directing light through an image on a first film, through the lens and onto the sensor, to convert the image into a corresponding image signal. The frame, lens and sensor are moved as a unit away from the gate by urging the frame away from the gate. At least a portion of the gate is modified (for example, by replacing a corresponding portion or moving a portion such as a guide, or by adjusting an existing portion of the gate) to accommodate a second film of a width different from the first film. The frame is moved back into the scanning position so that at least part of an image on the second film in the gate will be focussed by the lens onto the sensor. Light can then be directed through an image on the second film, through the lens and onto the sensor, to convert the image into a corresponding image signal.
In one aspect of the method, at least the part of the image on the second film is focussed by the lens onto the sensor without movement of the lens with respect to the frame in a direction toward or away from the gate. In another aspect of the method, there is provided a method of scanning images carried by elongated films, using a scanner having a gate, a frame, at least two lenses attached to the frame, and a sensor attached to the frame (which scanner may particularly be a scanner of the present invention). This aspect is essentially the same as the method described above, and additionally includes moving the first one of the lenses out of the optical axis and moving a second one of the lenses into the optical axis (this typically being done before directing light through an image on the second film).
The present invention allows a scanner lens system to be pulled back from a film gate to allow access to it, while the lens system can be rapidly repositioned over the film gate in a correct focal position relative to the sensor. This is particularly useful where some aspect of the gate must be modified, just as when one part is adjusted or exchanged to accommodate a filmstrip of a different format and which must be imaged onto the sensor by a different lens.